Our proposed research is to study the aging effects in human lens low molecular weight proteins and cataracts. we are especially interested in the heavy and light molecular weight gamma crystallins, beta crystallin and an uncharacterized lens protein which we observed. Furthermore we like to determine the changes these proteins undergo in development of human senile cataract. Our preliminary studies revealed that the aging effects observed in the low molecular weight human normal lens proteins are generally similar to those observed in the bovine lens. What changes occur or what mechanism is involved which is responsible for the production of heavy molecular weight gamma crystallins found in bovine and human lens requires further investigation. Moreover we found that a shoulder peak of light molecular weight human gamma crystallin fraction appeared to have a molecular weight of 11,000. This protein was an unexpected finding in normal human lens. We wish to pursue this observation in detail. Biochemical analyses and immunochemical studies will characterize these proteins in human and bovine lenses.